Setts



Get. 16, 1928.

' V. R. LAWSON METHOD OF LOADING R BER HEEL BLANKS WITH WASHERS AND T F0 I E IN SAME I Flled 7 4 2 Sheets-Sheet 1 UB OOL May 1 Oct. 16, 1928.

V. R. LAWSON METHOD OF LOA G RUBBER HEEL BLA WASHERS A T FOR USE IN S Filed a 5 WITH 2 Sheets-Sheet 2 Patented Oct. 16, 1928.

UNITED STATES VICTOR R. LAWSON, OF BOSTON, MASSACHUSETTS, ASSIGNOR '10 LAWSON-WHITE- HEAD COMPANY, OF

SETTS.

BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHU- HETHOD 0] LOADING RUBBER HEEL BLANKS WITH WASHERS AND TOOL FOR USE IN SAME.

Application filed May 7, 1924. Serial No. 711,694.

This invention relates to processes of manufacturing rubber heels and to apparatus adapted especially for use in practicing such processes.

It is the universal practice to embed a series of washers in a rubber heel to receive the nails or other fastenings by means of which the heel is secured to the heel base of a shoe. It has been the usual practice heretofore to place these washers on pins located in the cavity of a heel mold, then press a heel blank, slug, or biscuit on these pins and force itinto the cavity bythe pressure of the top plate of the mold. The placing of the washers on the pins is a troublesome operation, particularly since this work must be done while the molds are hot, and with a view to eliminating the various objections that attend this practice, it has been proposed heretofore to load therubber heel blanks or biscuits with washers prior to the molding operation, and then to mold and vulcanize these blanks at any convenient time thereafter. It is important, of course, that the washers be arranged in the blank in substantially the same positional relationship which they are to bear to each other in the finished heel so that when the loaded biscuit is placed in a heel mold the washers will register accurately with the pins in the mold. While, as above stated, this method has been proposed heretofore, and machines have been designed for performing the biscuit loading operation, it has been found very difficult to handle the wide range of stocks that are en countered in different rubber heel plants. That is, the unvulcanized stock of which the heel blanks or biscuits are made, is sometimes very plastic and putty-like in consistency, having very little resiliency, while other stocks, on the contrary, are very tough and elastic and offer serious resistance to the embedding of washers in them.

The-present invention deals with the problem presented by these conditions, and it aims to improve both the methods of and apparatus for inserting washers in rubber heel blanks with a View to dealing successfully with the different kinds of rubber heel stocks. It is an especially important object of the invention to devise instrumentalities that will eflectually embed washers in rubber heel stocks of any character that may reasonably be expected to be met in practice.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claims.

Referring now to the drawings,

Figure 1 is a vertical cross sectional view showing a tool embodying this invention for practicing the present method;

Fig. 2 is a cross sectional view on the line 52- 2, Fig. 1; I r

Fig. 3 is a cross sectional view on the line 3-3, Fig. 2;

Figs. 4, 5 and 6 are cross sectional views showing successive steps in the rocess of forcing a washer into a rubber hee blank or biscuit;

Fig. 7 is a perspective view illustrating certain steps in the operation of loading a rubber heel blank with washers; and

Fig. 8 is a cross sectional view showing the method of supporting the washers in a mold during the molding and vulcanizing operation.

Referring first to Figs. 1, 2 and 3 it will be observed that the tool or instrument there shown includes a hollow tubular guide or needle 3 having a point of approximately conical form comprising a series of needlelike fingers 4 which preferably are formed integral with a shouldered shank 5. This device preferably is made of steel and is suitably tempered. It is supported in an upright position in a holder 6 which may also su port a gang of these guides, and the shouldered shank 5 has a limited movement between an upper shoulder 7 and a lower shoulder 8 in the holder 6. Mounted within the support 6 is a plunger 9 which is arranged to reciprocate axially through the guide, and the upper end of this plunger is provided with a short central pin or tip 12 which is designed to center a washer W which is to be forced into the heel blank.

The rubber heel blank or biscuit which is to be loaded with washers may be supported in any convenient manner. As shown in Fig.

1 the blank B is held in a cavity formed in a plate 15 having one or more holes 16 in the lower side thereof for the passage or the guiding device 3. A presser foot 17 bears on the upper face of the blank and supports it against the thrust of the tool.

It will now be understood that when the plunger 9 is forced upwardly it will. carry the washer W up with it until the edge of the Washer strikes the needles 4-, at which time the entire guiding device will be picked up by the plunger and washer and carried upwardly, the point of this guide being forced into the blank 3. This upward movement will be limited by the upper shoulder 7, but the point of the needles 1 will all be forced into the blank simultaneously and to substantially the same depth. This step in the process is illustrated in Fig. t. As the plunger 9 continues to rise, it will force the washer W upwardly between the needles t thus spreading them apart, as shown in Fig. 5, a d causing them to press back the stock laterally away from a given point in the blank B and for a substantial depth in said blank. This forms a hole in the blank into which the washer is pushed flatwise as the plunger continues its upward movement. These operations are continued, the washer being forced upwardly by the plunger, as shown in Fig. 5, until it passes beyond the ends of the needles l, and

the plunger holds the washer at the desired depth in the blank while the needles snap in below the washer and the stock in the blank springs inwardly over the margin of the washer and locks it in the blank. The upper end of the plunger 9 is reduced in diameter and is tapered, as best shown in Fig. 5, to lacilitate this action. The needles are next withdrawn by pulling the plunger downwardly, and the st ck spreads inwardly over the washer still further, leaving the washer securely locked in the blank, as shown in Fig. 6.

As the plunger 9 withdraws it carries the guide 3' downwardly with it until the shank 5 of this guide strikes the lower shoulder 8, at which time the movement of the guide is stopped and the plunger continues its return to its initial position.

For the purpose of presenting the washers in operative relationship to the plunger, the

support 6 preterablyis provided with a lateral pocket 18, and an inclined washer chute 19 leads into said pocket. A washer is di charged-into the pocket through this chute while the plunger is at the upper part of its stroke, and it rests in the dotted line position X, Figs. 1 and 3, while the plunger is descending, and then drops over upon the top of the plunger as soon as the plunger reaches the lower limit of its movement. This washer is then positioned properly to be inserted in the heel blank.

The loading of the blank B may be continblank, care being taken to have the guiding devices so positioned with reference toeach other that they will insert the washers in the positional relationship which it is desired to have them bear to each other in the finishedheel.

Subsequently this loaded blank is placed in a heel mold, such, for instance, as that shown in Fig. 8, the washers W resting on the shoul dered pins 21 with which a heel mold 20 ordinarily is equipped. ll hen the top plate of the mold is forced down into its final position it will press the stock of the blank B down into the cavity in the mold and seat the washers W more iirnily on the pins 21 thus relatively repositioning the washers and the rubber body of the heel, and bringing them into their permanent relationship to each other. operation is then performed in the usual, or

convenient, manner. I

In inserting the washers in a heel blank they are so spaced that they bear substantiah ly the same relationship to each other that they do in the finished heel, but this relation-. ship may not be enact, a slight variation or tolerance in the spacing being permissible, and a certain departure from this spacing sometimes being advisable, in order to coinpensate for the expansion of the blank which takes place when it'is placed in a heel inold.

It will now be appreciated that this invention overcomes completely the objections The molding and vulcanizing I T that have been experienced heretofore in embedding washers in rubber heel blanks. This method permits the loading of blanks with washers positively and with absolute certain- 'ty as to results, regardless of all ordinary variations in the character of the stock from which the blanks are made. Furthermore, the fact that the washers can be embedded to a predetermined depth which can-be accurately controlled is a great practical advantage. lhat is, some diiliculty has been experienced heretofore in regulating the depth of the washers in the blank. If they are located too deeoly thewashers will not be engaged by the points off the pins when the blanks are placed in the heel cavities of the molds, and this is likely to result in the production of in1 perfect heels. The present invention, however, ensures the location of all the washers in the blank at substantially the same depth,

and this depth can be so controlled that the washers will be sure to be located on the pins when the blanks are placed in the mold cavities.

. It will be understood that the process pro 7 ratus and that the invention is not limited to embodiment in the form shown.

Having thus described my invention, what I desire to claim as new is:

1. That improvement in the process of loading a rubber heel blank with washers which consists in making a hole in the blank, pressing back the stock forming the walls of the hole and restraining its tendency to return to its original condition, inserting a washer flatwise in said hole, and releasing the restrained stock and permitting it to spread freely inward over the margin of the washer and lock it in the blank while holding the washer at the desired depth.

2. That improvement in the process of loading a rubber heel blank with washers which consists in forming a hole in the blank b spreading the material of the blank 1aterally away from a given point for a substantial depth in the blank, inserting a washer flatwise in said hole, restraining the tendency of the stock to return to its original condition until the washer has been positioned at the desired depth in the blank, and then releasing the restrained stock and allowing it to spread over the margin of the washer and lock the washer in the blank.

3'. That improvement in the process of loading a rubber heel blank with washers which consists in making a hole in the blank, pressing back the stock forming the walls of the hole and restraining its tendency to return to its original condition, inserting a washer fiatwise in said hole while guiding the edge of the washer on the instrumentalities that hold said stock in its restrained position, holding said washer at the desired depth in the blank, and then releasing the restrained stock and allowing it to spring inwardly over the margin the same point and to substantially the same depth in the blank, pushing a washer flatwise into the blank while guiding the edge of the washer on said needles, whereby said needles will be spread apart and caused to form a hole in the blank to receive said washer, continuing said movement of the washer until it passes beyond theends of the needles, and then withdrawing the needles.

5. A device for loading a rubber heel blank with washers, comprising a series of needlelike members arranged to form a tubular guide having an end of approximately conical form, and means for forcing a washer through said guide.

6. A device for loading a rubber heel blank with washers, comprising a series of needlelike members arranged to form a hollow conical guide for a washer, a support forsaid members, and a plunger movable axially within said guide.

.7. A device for loading a rubber heel blank with washers, comprisinga series of needlelike members arranged to form a hollow conical guide for a washer, a support for said guide having a lateral opening for the admission of a washer, and a plun er for forcing said washer through said guide.

8. A device for loading a rubber heel blank with washers, comprising a hollow guide of approximately conical form comprising a series of independently movable resilient members adapted to guide a washer, and a tubular shank integral with said members and supporting them.

9. A device for loading a rubber heel blank with washers, comprising a hollow guide of approximately conical form comprising a series of independently movable resilient members adapted to guide a washer, a hollow support for said members, a plunger movable through said guide, and means for guiding a washer into position to be engaged by said plunger and forced through said guide.

VICTOR R. LAWSON. 

